Karl mischke



(No Model.)

K. MISCHKE;

. SCREW CUTTING DIE HEAD.

No. 606,223. Patented June 28,1898.

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ATTO EYS iUnurnn Sra'rns ATENT @rrren.

KARL MISOHKE, OF NEYV YORK, N. Y.

SCREW-CUTTING DIE HEAD.

SPECIFICATION forming part of Letters Patent No. 606,223, dated June 28, 1898.. Application filed February 8,1897. Renewed October 22, 1897. Serial No. 656,066. (No model.)

To aZZ whom it may concern;

Be it known that I, KARLIVIISCHKE, a citizen of the United States, residing in the city, county, and State of New York, have invented certain new and useful Improvements in Screw-Outting Die-Heads, of which the following is a specification.

This invention relates to certain improvements inscrew-cutt'ing die-heads in which the threading action is automatically interrupted by the opening of thedies when the required length of .the thread has been cut, so that the reverse rotation of the threaded article is unnecessary and the same removed directly from the die-head.

The invention consists of a screw-cutting die-head which comprises a tubular main piece or stock, guided spring-actuated jaws pivoted to said stock, said jaws being provided with adjustable screw-cutting dies, a spring-actuated looking-plate by which the jaws are locked in closed position for cutting the threads, and means for releasing said jaws from the locking-plate in accordance to the required length of thread cut by the jaws.

The invention consists, further, of certain details of construction by which the reliable functioning of the die-head is secured and the clogging of the pivoted jaws by means of chips is prevented.

In the accompanying drawings, Figure 1 represents a front elevation of my improved screw-cutting die-head, showing the die-car'- rying jaws in locked position for the cutting action. Fig. 2 is a front elevation of the diehead, showing the jaws and dies in position after they are opened by the action of the un-' locking mechanism. Fig.8 is a side elevation of my improved die; and Fig. 4 is a V61? tical section of the same on line 4: 4, Fig. 2. Fig. 5 is a sectional view of the locking-plate,

showing a modification of the means for re-f leasing the jaws.

A represents a tubular stock which is placed in the center of the screw-cutting machine or into the turret-head of a monitor screw-cut ter. The tubular stock A isiprovided with 'a head A, that extends at diametrioal points from the tubular stock A, to the lowerpart of which isapplied a stationary pivot afor' the pivoted spring-actuated die-carrying jaws l3 13, while to the upper end of the head A is applied a T-shaped guide-piece C, which engages the upper recessed ends of the jaws, so as to guide them in their lateral-motion when opening or closing. The T-shaped guide 0 holds the jaws firmly in position during the to by set-screws d and adjusting-screwsd,

that press onthe ends of the screw-cutting dies B. Diiteren't sizes of cutting-dies can be used with the jaws, so as to produce the thread ing of articles of various diameters at any desired pitch of screw. The lower part of the jaws above the pivot are provided with sockets, into which is inserted a helical cushioning-spring,the tension of which is overcome when the jaws are placed into closed and locked position for cutting screw-threads. This spring serves to move the jaws apart as soon as the locking mechanism for the same is released.

The locking mechanism of the jaws consists of a locking-plate E, which is interposed between thehead A of the stock A and'the jaws B B, as shown in Figs.3 and 4. The lockingplate E is provided with a tubular shank E,

whichis guided in the tubular stock A, said provided with forward projecting pins f, which engage corresponding holes 'f' in. the jaws B B when the jaws are moved together, the interlocking of the pins with the holes beingaccomplished by a cushioning-spring f which is located in a socket f of the head A,

and which engages a similar socket in the rear of the locking-plate, as shown clearly in Figs. 3 and 4c. The locking-plate E serves by its pins f to lock the jaws in rigid position, so that the cutting action of the dies is prod ueed; also, that the dies are in position for producing a screw-cutting action. Between the jaws B B is arranged at the upper part of the die-head a device for releasing the locking-plate from the jaws when the required length of thread on'the article to be threaded is out. This releasing deviee is provided with two shankrods g, that are secured to the locking-plate by suitable set-screws, said releasing device being readily adjusted in forward and backward direction on the plate according to the length of the thread to be cut. The releasing device consists of two parts-a guide portion G, to which the shanks g are attached, and an adjustable portion G, that is guided along said main portion and firmly clamped thereto by a set-screw g, the head of which engages the head of the releasing device, as shown in Figs. 1 and 2.

The lower end of the head G is made tapering, so as to extend downward between the screw-cuttingdiesB,sothatwhen the shoulder or larger portion of the article to be threaded abuts against the lower end of the head G, as shown in Fig. 4, the releasing device is moved in backward direction with the locking-plate against the tension of the cushioning-springs until the locking-pins f clear the openings f of the jaws and permit thereby the instant opening of the latter, together with the cutting-dies, by the tension of their spring, so that the threaded article can be readily removed from the die without reversing the motion of the machine in order to allow the removal of the work. The chips that are formed by the dies during the cutting action are dropped into the center trough of the guard-plate and removed from the same from timeto time. Then the jaws are opened on the release of the locking-plate, they are held in open position by the shoulders at the ends of the T-shaped guide 0, against which the pins at the upper ends of the jaws abut, as shown in Fig. 2. For cutting the next thread the jaws have to be closed again, which is accomplishedby moving them toward each other until they are rengaged by the locking-pins of the spring-cushioned locking-plate.

The releasing device being arranged in front of the jaws B B, so as to be actuated by a projection on the article to be threaded, can also be arranged at or near the center of the tubular shank of the locking-plate, as shown in Fig. 5.

The modified releasing device consists of a threaded projection h, secured at a convenient point in the interior of the tubular shank of the locking-plate, so as to be accessible to the mechanic from the front end of the thread ing-tool. A threaded rod 71, having a head 7L2 suitably notched to be operated by a screwdriver, is passed through said projection. By properly adjusting said rod in said threaded projection the exact length of thread desired can be cut on a rod of any length or dimension within the capacity of the die-head. When the predetermined length of thread has been cu t, the end of the rod will abut against the head of the threaded rod h and force back the locking-plate, thus releasing the jaws B B in the manner before explained. The opening of the jaws is produced thereby in the same manner, and it is immaterial whether the releasing device is located in front of the jaws or at the center of the shank of the locking-plate, as the effect obtainednamely, the opening of the jaws and the interruption of the cutting of the thread by the releasing of the locking mechanism from the j aws-is produced whether the releasing device is located in one position or the other.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. The combination, with a tubular stock, of spring-actuated jaws pivoted to said stock, screw-cutting dies in said jaws, a spring-actuated locking-plate provided with a tubular shank whereby it is guided in said tubular stock, and a releasing device carried by said locking-plate, substantially as set forth.

2. The combination, with a tubular stock, of spring-actuated jaws pivoted to said stock, screw-cutting dies in said jaws, a spring-actuated locking-plate located in front of said stock and provided with a tubular shank guided in said tubular stock, and a releasing device carried by said locking-plate, substantially as set forth.

3. The combination with a tubular stock, of spring-actuated jaws pivoted to said stock and provided with locking-orifices, screw-cutting dies supported by said jaws, means for guiding and stopping said jaws, a spring-cushioned locking-plateprovided with a tubular shank, forwardly-proj ectin g lockin g-pins carried by said locking-plate, a guard-plate carried by said locking-plate and located below the screw-cutting dies, and an adjustable releasing device carried by said locking-plate, substantially as set forth.

at. The combination with a tubular stock, of spring-actuated jaws pivoted to the same, screw-cutting dies supported by said jaws, a T-shaped guide-head for engaging the upper ends of said jaws, means for arresting the outward motion of said jaws, a spring-cush- .ioned locking-plate having a tubular shank guided by said stock, said plate being adapted to interlock with the jaws when they are in closed position, and a longitudinally and. laterally adjustable releasing device connected with the locking-plate, substantially as set forth.

5. The combination with a tubular stock having a T-shaped head,spring-actuated jaws pivoted to the lower part of the head and pro- IO fices in the jaws, and a releasing device at tached to said locking-plate provided with an adjustable head, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing witnesses.

KARL MISOHKEL Witnesses:

GEO. W. JAEKEL, WILLIAM B. ROBERTS. 

